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1.
The larval stage of fishes is critical in determining their dispersal, survival and recruitment, but little is known of the larval behaviours and tolerances of amphidromous fishes, particularly in New Zealand. We report the results of a series of observational and experimental studies on bluegill bully (Gobiomorphus hubbsi), including spawning sites and behaviours, larval characteristics at hatch, phototactic responses of larvae, and larval survival at different salinity levels. Spawning primarily occurred in the lower reaches of the river, and larvae from different nests exhibited marked differences in, and trade-offs between, larval characteristics at hatch, potentially affecting larval success. Larvae were positively phototactic to intense light, an unexpected result based on diel drift patterns and international research. Finally, larvae exhibited markedly higher survival rates when reared at intermediate salinities compared to freshwater or seawater, suggesting estuaries may play an important role as nursery grounds for bluegill bully and other amphidromous fish. 相似文献
2.
水平光梯度下三疣梭子蟹趋光反应的实验研究 总被引：4，自引：0，他引：4
三疣梭子蟹(Portunus trituberculatus(Miers))分布黄海、东海和日本近海,其经济价值高、资源丰富,是一种重要的海产品,也是一种大有捕捞前途的渔业资源。然而,由于对它的趋光生理生态学问题缺乏研究,致使捕蟹技术长期未能得到改进,迄今基本上仍停留在底拖网和笼诱捕的旧渔法水平上[1-3],捕捞量的提高受到很大限制。 相似文献
3.
《Journal of Sea Research》2007,57(2-3):91-103
Factors contributing to population growth through strong year-class formation have driven a century of directed research in fisheries science. A central discovery of Hjort's paradigm was that multiple generations overlap and longevity is matched with frequency of strong recruitments. Here, I elaborate on this tenet by examining how intra-population modalities in spawning and early habitat use favour population resiliency. A modern theory that has application is the storage effect [Warner, R.R., Chesson, P.L., 1985. Coexistence mediated by recruitment fluctuations – a field guide to the storage effect. Am. Nat. 125, 769–787], whereby spawning stock biomass accumulates each year so that when early survival conditions are favourable, stored egg production can result in explosive population growth. I review two early life history behaviours that contribute to the storage effect: split cohorts (i.e., seasonal pulses of eggs and larvae) and contingent behaviour (i.e., dispersive and retentive patterns in early dispersal). Episodic and pulsed production of larvae is a common feature for marine fishes, well documented through otolith microstructure and hatch-date analyses. In temperate and boreal fishes, early and late spawned cohorts of larvae and juveniles may have differing fates dependent upon seasonal and inter-annual fluctuations in weather and climate. Often, a coastal fish may spawn for a protracted period, yet only a few days' egg production will result in successful recruitment. In these and other instances, it is clear that diversity in spawning behaviour can confer resilience against temporal variations in early survival conditions. Although many factors contribute to intra-population spawning modalities, size and age structure of adults play an important role. Contingent structure, an idea dating to Hjort (herring contingents) and Gilbert (salmon contingents), has been resurrected to describe the diversity of intra-population modalities observed through otolith microchemical and electronic tagging approaches. Retentive and dispersive behaviours confer resiliency against early survival conditions that vary spatially. Examples of contingent structure are increasingly numerous for diadromous fishes. Here, a nursery habitat associated with a contingent behaviour may make a small contribution in a given year, but over a decade contribute significantly to spawning stock biomass. For flatfish and other marine fishes, contingent structure is probable but not well documented. Proximate factors leading to contingent structure are poorly known, but for diadromous fishes, time of spawning and early life history energetic thresholds is hypothesized to lead to alternative life cycles. Here again time of spawning may lead to the storage effect by hedging against spatial variance in early vital rates. Managing for the storage effect will be promoted by conservation of adult age structure and early habitats upon which both strong and weak year-classes rely. 相似文献
4.
The behaviour of a talitrid amphipod, Orchestoidea tuberculata Nicolet 1849, was investigated for populations inhabiting two exposed sandy beaches in south central Chile to evaluate orientation capabilities with respect to sun azimuthal changes and landscape. The study beaches (Calfuco and La Misión) were backed by high cliffs but differed in shoreline orientation. Under test conditions of dry substrate, both populations oriented seawards using celestial cues when landscape vision was screened off and showed a higher concentration seawards when they could see the landscape suggesting additive effects of these cues. The absence of a phototactic response to the sun implies the involvement of an inner circadian clock, as the experiments were conducted at different times of the day. The distribution of juveniles was more concentrated than adults in the trials, a result in accordance with their tendency to occupy a zone located closer to the water than adults. Our results suggest that the Calfuco population was oriented to its shoreline, while animals at La Misión tended to deviate from the expected direction and their distribution was more scattered. This observed difference between the populations may be related to the higher human impact on the latter beach, which was more intensively used for recreation and periodically cleaned, removing the wrack. The comparison of results on orientation of O. tuberculata with those of different sandhopper species contributes new phylogenetic insight concerning this important adaptation. This study not only represents an extension of contemporary knowledge of behavioural adaptations of beach amphipods to coasts differing geographically and ecologically, but also analyses orientation in a southern Pacific species of talitrid amphipod for the first time. 相似文献
5.
诱鱼灯光场计算及其对光诱鱿鱼浮拖网作业的影响 总被引：9，自引：0，他引：9
本文运用诱鱼灯光照度的有关公式,计算了光诱鱿鱼浮拖网作业中的光场分布及变化,结合鱿鱼趋光行为习性,分析现有渔具渔法的适应性。结果表明;使用１６盏铊铟灯水上灯,诱鱼最大水平距离比仅使用水下灯增加约６８０倍,但水上灯从１６盏增加到４０盏地,从经济角度分析不很理想;在集鱼过程中,关闭最后一组水上灯后,应有白炽灯经过降压后再地渡到水下灯集鱼;导鱼灯在向网口移动的过程中应继续降低低电压; 相似文献
6.
几种舌鳎的形态和生长特性的比较 总被引：4，自引：0，他引：4
由于我国近海传统经济鱼类资源的衰退,渔业资源的增殖和经济品种的养殖已成为海洋渔业经济的重要组成部分。在增养殖品种中 ,经济价值高、生长快、对环境耐受力强的品种自然成为首选的对象。舌鳎属（Ｃｙｎｏｇｌｏｓｓｕｓ）鱼类广布在我国近海的底层水域,该属鱼活动范围小、洄游距离短、围捕率高 ,它们食谱广、生长迅速、初次性成熟早,对环境的适应能力强 ,作为近海海湾的增养殖对象已引起了人们的关注。作者等自１９８５年起对舌鳎属的半滑舌鳎、宽体舌鳎和短吻舌鳎的生物学进行了究 ［１～６］,本文进一步对半滑舌鳎((Ｃｙｎｏｇｌｏｓ… 相似文献
7.
Shallow soft-bottom habitats including mangroves and mudflats provide important nursery functions for juvenile fishes, but little information exists concerning the relative nursery value of these habitats for juvenile fishes. We compared the potential of a mangrove and a mudflat in a semi-enclosed bay in Hong Kong to serve as fish nurseries by measuring species composition, dietary composition, gut fullness and diet breadth of juvenile fishes. Fish abundance was higher in mangrove than mudflat, but species richness was almost similar between the two habitats. After excluding Ambassis gymnocephalus, which was found mainly in the mangrove, difference in fish abundance between the two habitats was small. The gut fullness and diet breath of most species did not differ between mangrove and mudflat, suggesting that the two habitats were very similar in terms of providing feeding opportunity for juvenile fishes. While the importance of mangrove as nursery of fishes has been repeatedly emphasized, our data suggest that other soft-bottom habitats, such as mudflats, are also important and need to be protected. 相似文献
8.
R. D. M. Nash 《Marine Ecology》1982,3(2):161-178
Abstract. The diel behaviour of communities of small demersal fishes was studied in situ on the west coast of Scotland using trawling, diving, underwater television and underwater time-lapse photography techniques. Lumpenus lampretaeformis and Pomatoschistus norvegicus were shown to have crepuscular behaviour patterns. Lesueurigobius friesii was a day active fish, spending the night close to or within its burrow and feeding through the day. Disruptions to this behaviour pattern occurred at high abundances of gadoids and during the spawning season. The fish community as a whole showed a crepuscular periodicity. The various observational methods are discussed. There did not appear to be any close association between Lesueurigobius friesii and the decapod Nephrops norvegicus. 相似文献
9.
《African Journal of Marine Science》2013,35(2):205-214
The South African abalone Haliotis midae is commercially exploited and seriously threatened by overfishing. This not only affects the species itself but potentially the functioning of the ecosystem because of associated changes in community structure. The nature of effects that can follow the loss or reduction of a species depends in part on its position in the foodweb and its feeding behaviour. To assess the ecosystem effects of the adults and subadults of this previously abundant herbivore on the south-west coast of South Africa, we studied their diet and mode of food procurement by (a) in-field observations of adult and subadult abalone, (b) analysis of the gut contents of adults, (c) comparison of diet with the availability of algae, and (d) a mesocosm experiment on subadult feeding behaviour. Both field and dietary studies showed that adults subsist mainly by trapping drift kelp, but also occasionally graze on attached algae such as Plocamium spp., and feed in a manner that is highly selective, with drift kelp constituting 95–98% of the diet, and several species of common algae being avoided. In the mesocosm experiment, subadults preferentially fed on drift kelp, but emerged at night to a greater extent to graze on microflora if no drift material was available. Their propensity to emerge was, however, reduced if the rock lobster Jasus lalandii was present. Collectively, this evidence indicates that any ecosystem effects that subadults and adults of H. midae have as grazers will be weak because they feed mainly by trapping drift material, and the frequency of grazing and the incidence of consumption of attached algae are low. 相似文献
10.
渤海鱼类区系分析 总被引：12，自引：0，他引：12
关于渤海的鱼类区系,张春霖等(1955)曾报道了116种;林福申1)根据1958年6月-1959年11月渤海大面试捕资料(其间12-3月未调査)记载了渤海底层鱼类74种,他在分析了这些鱼类的区系性质后提出,其中暖水性鱼类19种、温水性鱼类44种、冷温性鱼类11种,并认为渤海鱼类的区系性质属温水性。根据中国科学院海洋研究所1982年4月至1983年5月在渤海进行的底拖网逐月试捕调査和1983年6,7月上层拖网试捕调査资料,以及有关文献和本所历年来的采集记录鉴定,渤海已记录的鱼类有19目,66科,156种,其中我所试捕调查获108种,文献和采集记录补充了48种。本文根据以上资料,对渤海鱼类的种类组成和区系性质进行分析。渤海鱼类名录和种的区系性质按分类系统(成庆泰、郑葆珊,1987)列于附表。由于调査范围、时间及捕捞工具有限,遗漏种类在所难免，但作者认为上述材料已基本上能反映渤海鱼类的全貌。 相似文献
11.
R. J. Beamish K. D. Leask O. A. Ivanov A. A. Balanov A. M. Orlov B. Sinclair 《Progress in Oceanography》1999,43(2-4)
We describe the distribution and abundance of the midwater fish community, between 200 m and 500 m, in the North Pacific. The main area of interest was the Subarctic Pacific gyres, but we include species from the Bering Sea and the Sea of Okhotsk. There were 196 species identified in each gyre, 38 of which were common to both gyres. The most abundant species belong to the family Myctophidae and the most ecologically important myctophid probably is Stenobrachius leucopsarus. This species could have a biomass of approximately 21 million tonnes (t) in the Subarctic Pacific (including the Bering Sea and Sea of Okhotsk). S. leucopsarus is a small (about 8 cm maximum length) fish that lives up to 7 years. It is prey for a variety of other fishes, birds and mammals and may migrate into the mixing layer each evening where it feeds mainly on euphausiids and copepods.The total abundance of midwater fishes appears to be large relative to total catches of other fish in the same areas. The vertical migratory behaviour of some of the residents provides a mechanism to transfer production out of the mixing layer. The movement into the surface layer by some fishes at night indicates that dynamic changes occur in the midwater community between the day and night, and the ecosystem dynamics in the surface layer are different in the day and in the night. This behaviour and the huge biomass relative to commercial species means that the dynamics of fish communities in the Subarctic Pacific are complex and need to be studied over a 24 hour period. The large biomasses may eventually attract commercial interest, thus it is important to establish international, cooperative programs now to learn more about the dynamics of these populations and the relationships with other species. 相似文献
12.
Larval fishes were sampled in the Kwaaihoek surf zone on the south east coast of South Africa. On six occasions between February and May 2002, larval fishes were collected in two habitat types identified in the inner surf zone using a modified beach-seine net. The surf zone habitats were classified as either sheltered trough areas or adjacent exposed surf areas. Temperature, depth and current measurements were taken at all sites. Trough habitats consisted of a depression in surf topography characterised by reduced current velocities and greater average depth than adjacent surf areas. In total, 325 larval fishes were collected. Of these, 229 were collected in trough and 96 in surf habitats. At least 22 families and 37 species were represented in the catch. Dominant families were the Mugilidae, Sparidae, Atherinidae, and Engraulidae. Dominant species included Liza tricuspidens and Liza richardsonii (Mugilidae), Rhabdosargus holubi and Sarpa salpa (Sparidae), Atherina breviceps (Atherinidae) and Engraulis japonicus (Engraulide). Mean CPUE of postflexion larvae of estuary-dependent species was significantly greater in trough areas. The proportion of postflexion larval fishes in trough habitat was significantly greater than that of preflexion stages, a result that was not apparent in surf habitat sampled. CPUE of postflexion larvae of estuary-dependent fishes was negatively correlated with current magnitude and positively correlated with habitat depth. Mean body length of larval fishes was significantly greater in trough than in surf habitats. These results provide evidence that the CPUE of postflexion larvae of estuary-dependent fishes is higher in trough habitat in the surf zone and this may be indicative of active habitat selection for areas of reduced current velocity/wave action. The implications of this behaviour for estuarine recruitment processes are discussed. 相似文献
13.
A long-term mark-recapture study was used to assess the movement patterns of surf-zone fishes in the St Lucia Marine Reserve, a marine protected area within the iSimangaliso Wetland Park, a World Heritage Site on the east coast of South Africa. Between 2001 and 2013, 6 613 fish from 71 species, caught by hook and line, were tagged at four sites within and adjacent to a no-take marine sanctuary area. A total of 1 004 (15.2%) recaptures were made from 17 species. The majority (82.4%) of these species displayed station-keeping behaviour, whereas only three were classified as wider-ranging species, and no species with discernible migratory behaviour was observed. Findings for five species with the highest recapture rates, namely Pomadasys furcatus, Epinephelus andersoni, E. marginatus, Dinoperca petersi and Lutjanus rivulatus, are presented in greater detail. Recapture rates ranged from 7% to 50% and time at liberty from 0 to 3 163 days. Individuals of all five species displayed station-keeping behaviour, with the 95th percentile of intra-study-site movements varying between 200 and 1 025 m (linear distance). However, four of the five species also displayed some ranging behaviour and made exploratory excursions ranging from 3.5 to 125 km, in both northerly and southerly directions. The dominance of station-keeping behaviour suggests that the St Lucia Marine Reserve sanctuary zone provides an important refuge for these species, with some export to adjacent areas. 相似文献
14.
There is a growing need to incorporate biotic interactions, particularly those between predators and their prey, when predicting climate-driven shifts in marine fishes. Predators dependent on a narrow range of prey species should respond rapidly to shifts in the distribution of their prey, whereas those with broad trophic adaptability may respond to shifts in their prey by altering their diet. Small pelagic fishes are an extremely important component of the diet of many marine predators. However, their populations are expected to shift in distribution and fluctuate in abundance as the climate changes. We conducted a comparative study of the seasonal diet of adult Pomatomus saltatrix over two periods (June–December 2006 and 2012) and examined the available data on small pelagic fishes biomass in a global hotspot (the coastal region of southern Angola, southern Africa) to gain an understanding of the tropic adaptability of the species. Despite a drop (630 000 t to 353 000 t) in the abundance of their dominant prey (Sardinella aurita) in the region, it remained the most important prey item during both study periods (Period 1 = 99.3% RI, Period 2 = 85.3% RI, where %RI is a ranking index of relative importance). However, the diet during Period 2 was supplemented with prey typically associated with the nearshore zone. The seasonal data showed that P. saltatrix were capable not only of switching their diet from S. aurita to other prey items, but also of switching their trophic habitat from the pelagic to the nearshore zone. These findings suggest that P. saltatrix will not necessarily co-migrate if there is a climate-driven shift in the distribution of small pelagic fishes (their dominant prey). Accordingly, understanding the trophic adaptability of predators is critical for understanding their response to the impacts of climate change. 相似文献
15.
André Padua Emilio Lanna Carla Zilberberg Paulo César de Paiva Michelle Klautau 《Marine Ecology》2013,34(1):56-61
Little is known about the recruitment and behaviour of sponge larvae, especially of the class Calcarea. The calcareous sponge Paraleucilla magna is very common in Southeast Brazil, where it is considered a cryptogenic species. This study quantified recruitment rates in shaded and illuminated habitats for 2 years in Rio de Janeiro, Brazil, and analyzed larval photoresponses of this species. Four structures, each containing a shaded and an illuminated surface, were exchanged every 3 months for 2 years. The number of recruits was quantified on each plate. In the laboratory, larvae of P. magna were placed in half‐shaded Petri dishes and the number of settlers in each side was counted after 24 h. Paraleucilla magna recruited continuously throughout the experiment. Recruits occurred in greater abundance on shaded surfaces than on illuminated surfaces, and the larvae were negatively phototactic in vitro. Despite the possible influence of other factors in the recruitment of sponges (such as sedimentation, competition and predation), the prevalence of P. magna in shaded habitats may also be related to larval choice. 相似文献
16.
利用彩色显示回声探测仪在南海北部水域中测到的图象进行调查底栖鱼类和ＤＳＬ的垂直移动；仪器的量程扩功能用于考察底栖鱼类的贴海底，超浮，聚薄层和扩散等情景；ＤＳＬ在黄错时期的聚层起浮，午液出现集群最密，黎时下降，解体；示出ＤＳＬ聚层的厚度及垂直移动的速度。 相似文献
17.
稀释技术^14C测年可靠性的研究 总被引：1，自引：0，他引：1
稀释技术~(14)C测年的关键在于本底气的稳定,稀释技术测定的最大年限取决于样品的含碳量。同一样品无机碳部分和有机碳部分的对比实验和不同测年方法的对比实验,都证明稀释技术测定的~(14)C年龄不但复现性好而且可靠。 相似文献
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ＵｓｅｏｆａｎｅｗｃｌｏｎｅｏｆＡｒｔｅｍｉａｐａｒｔｈｅｎｏｇｅｎｅｔｉｃａ（ＯＰ１）ｔｏｉｎｃｒｅａｓｅｇｅｎｅｔｉｃｖａｒｉａｔｉｏｎ￥／／ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｒｅａｒｅｐａｌｔｈｅｎｏｇｅｎｅｔｉｃａｎｄｂｉＳｅｘｕａｌｒｅｐｎｄｕ... 相似文献
20.
Two methods,tagging and ink injection,are used in the grouper releasing experiment.The studied fishes are the juvenile of Epinephelus akaara and Epinephelus awoara both artificially cultivated and caught from natural waters,and their wild adults.Experimental results show that the inhabiting behaviours for both juvenile and adult fishes show distinct regionality,which move within an area of 2n mile diameter 651 days and 48 days after being released,respectively,With the tagging method,the tagged fishes could only be recaptured in the year of release while,with the injection method,they could be caught in the lst,2nd and 3rd years,It is confirmed that in the cement tank,the tagged fishes lose their 1/3 tags.That means that the tagging method is not fit for the release research while the injection method is .Generally,the recaptured rates of injected fishes are 1.4-4.5%,3.1-13.4%and 2.7%for the lst,1nd and 3rd years,respectively. 相似文献